/Engine/Source/Runtime/AssetRegistry/Public/AssetRegistry/IAssetRegistry.h
Gets asset data for all assets in the registry. This method may be slow, use a filter if possible to avoid iterating over the entire registry.
bool GetAllAssets ( [TArray](API\Runtime\Core\Containers\TArray)< [FAssetData](API\Runtime\CoreUObject\AssetRegistry\FAssetData) > & OutAssetData, bool bIncludeOnlyOnDiskAssets ) const